PCT application WO 2008/074703 describes heteroaryl pyrrolidinyl and piperidinyl ketones which can be useful for treatment of diseases associated with triple reuptake inhibitors. Methods for the preparation of (3,4-Dichloro-phenyl)-((S)-3-propyl-pyrrolidin-3-yl)-methanone hydrochloride and its hydrates have been described in PCT application WO 2008/074703. However, these methods include a large number of individual reaction steps. Further, the methods known in the art exhibit a low yield or other disadvantages, which makes them unsuitable for the commercial large scale production.